This is exactly how I do it, two man job for sure,,
Originally Posted by Maris
When the enlarger head is too high and no amount of "ape hanger" position will reach the focus knob I get a friend in. One person watches through the focussing magnifier and calls "up", "down", "ok" while the other tweaks the focus knob.
Doing mural size enlargements is usually a two person job (in my darkroom at least) so the "focussing assistant" job already has a volunteer.
Sorry for the delay fellas... I got sick for a few days and totally forgot I'd posted this...!!! (great when you're posting in an emergency call for help, huh???). At any rate- yes, I think Mick and Maris/Bob pretty much have the idea. The whole problem is that it's a freestanding devere converted to wall mount. And I had to remove the fabulous focus shafts - since I didn't really want to make knob photograms everytime I made a print! I'm printing on a floor vacuum easel. So yeah - mick - it's on the floor on my knees. Then I have to stand halfway up to reach the locks and unlock... move the head a MICRON with my hands, lock... and check again - to discover it's even MORE out of focus. Great. It seems to take me in the neighbourhood of 30-100 of these iterations to nail the focus. I used to be able to do this by eye... (sigh).
So anyway- I was just looking for some sort of trick (I guess the opera glass thing doesn't sound all that bad) to 'cheat' the process somehow. I think I may try to cut off the old focus shafts and fix a flex shaft to them or something (like a long spring, etc) so that I can use them from the floor. It's not a quick fix - but probably the most time/effort effective...
Right, this is how you may be able to achieve a workable solution. I figured it was either a wall mounted free standing or tabletop unit. Yes a vacuum easel is almost mandatory but it must be in perfect alignment, I assume it is.
What you could do is this:- Go to an auto shop and purchase one of those ½" drive double jointed extensions, (actually a universal joint) mechanics use to screw and unscrew spark plugs and bolts in offset situations.
These are usually about 50mm long. You cut either your existing set of focusing rods to a stub and weld one of these jointed adaptor to the stub, or make up a set of stubs.
Then you buy (or manufacture) a long enough ½" rod with a T bar end which will allow you to kneel on the floor and move either your neg stage up and down, or your lens stage up and down. Locking the thing whilst you are on the floor, will depend upon just how long your arms are!
Once you are finished focusing, simply pull the shaft out of the universal socket extender, then expose to your hearts content.
I assume that you are already focusing in total darkness to aid your light gathering capacity?
This is just an alternative method. I will first state, for the record, my very impressive background in making murals...I have never even tried. You are using a vacuum easal on the floor. You have already found a means to provide alignment.
While the movement of the negative stage is very critical to the focus of the image the movement of the easal is not nearly as critical.
Why not start with half inch thick shims underneath the easel and focus as well as you can by eye while standing up. Then using a focus magnifier on the easal determine in the print becomes sharper by adding additional shims or becomes sharper by using thinner shims ?
I think i'll do something like that, Mick. I'll probably just get some springs - there's a rather good specialty spring company a few miles from here. I'll probably get a machine shop to cut off the shafts and weld the springs on... or something like that. Perhaps spray the spring with black rubber...
Claire - well - a vacuum easel tends to be rather THICK and built-in... so there's no moving it. However - I've been getting excellent results simply taping the paper to the easel without vacuum power. So maybe I'll try a shim -- but the shim has to be at least as large as the print... but not a bad idea...
I would stay away from shims under the easel.
Once the vacumn easel is aligned with the neg/lens stage I would not play with that. Getting that perfect alignment is a job in itself , this is tempting disastor with edge focus problems.
I like the idea of an extension arm and will persue this myself as I do a lot of odd hour printing where a second hand is not always availabe.
For my horizontal Durst there is an unit for fine focus at the wall but not sure if Deveere makes them and also for Omega which I also use for murals. Extension hands would really be the cats ass.
Yeah- well the easel's not going anywhere - it's a 2x4 frame which is glued to the floor with about 10 tubes of liquid nails and covered with 3/4" baltic birch ply... amazingly (and i didn't even try) the alignment was perfect from the get-go. I can shoot a 40x50 print at f/8 and get near perfect grain across the board...!! Pretty cool, that.
Don't know where or when I read it, but I did see something about a fellow who rigged up a second wheel, attached to the main focusing knob with a bicycle inner tube. This seems to me to be prone to over and under runs, but maybe a loop made of heavy canvas instead?
If I had been present at the creation, I would have given some useful hints for the better arrangement of the Universe.
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